Elsewhere, the Mori poll also shows Ukip dropping to 9%, down two points since last month. The party’s lowest share since November 2013. A result, which if repeated on election day, could see the Tories win up to 20 more seats than the Guardian’s most recent analysis of polls.

Satisfaction with Ukip leader Nigel Farage has also declined sharply. 30% are now satisfied with Farage, while one in two are dissatisfied, giving him approval ratings well below those of David Cameron (though still higher than both Ed Miliband and Clegg).

Labour is on 36% (up two points on last month), the Conservatives on 34% (+1), and the Greens are down one, and now on 7%. This is the second month in a row that Ipsos Mori has seen an increase in support for the two main parties. Support for Miliband’s party is up from 29% in December.

The number that think Miliband and Labour are ready for government is also on the rise. One in three (33%) think Labour is ready to form the next government and 21% think Miliband is ready to be prime minister, up from November’s 23% and 13% respectively. However, more than half still disagree that Miliband (63%) and his party (52%) are ready to govern.

Also troubling for the Lib Dems is the fact that the party’s current supporters are the least sure about their vote - 62% say they may change their mind, compared with 51% of both Labour and Ukip supporters, 42% of Tories, and 50% of the electorate as a whole.